CN117219775A - Ionic copolymer binder and preparation method and application thereof - Google Patents
Ionic copolymer binder and preparation method and application thereof Download PDFInfo
- Publication number
- CN117219775A CN117219775A CN202311421707.5A CN202311421707A CN117219775A CN 117219775 A CN117219775 A CN 117219775A CN 202311421707 A CN202311421707 A CN 202311421707A CN 117219775 A CN117219775 A CN 117219775A
- Authority
- CN
- China
- Prior art keywords
- ionic copolymer
- lithium ion
- binder
- copolymer binder
- phosphate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000011230 binding agent Substances 0.000 title claims abstract description 131
- 229920001577 copolymer Polymers 0.000 title claims abstract description 96
- 238000002360 preparation method Methods 0.000 title claims abstract description 33
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims abstract description 65
- 229910001416 lithium ion Inorganic materials 0.000 claims abstract description 65
- WJNRCWSLUSRJEM-UHFFFAOYSA-N 2-ethenylpyridine;phosphoric acid Chemical compound OP(O)(O)=O.C=CC1=CC=CC=N1 WJNRCWSLUSRJEM-UHFFFAOYSA-N 0.000 claims abstract description 57
- 239000002202 Polyethylene glycol Substances 0.000 claims abstract description 53
- 229920001223 polyethylene glycol Polymers 0.000 claims abstract description 53
- -1 acrylic ester Chemical class 0.000 claims abstract description 32
- 150000002500 ions Chemical class 0.000 claims abstract description 9
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 claims description 42
- 238000006243 chemical reaction Methods 0.000 claims description 32
- 238000002156 mixing Methods 0.000 claims description 31
- 238000010526 radical polymerization reaction Methods 0.000 claims description 30
- 239000002904 solvent Substances 0.000 claims description 28
- 239000000126 substance Substances 0.000 claims description 27
- KGIGUEBEKRSTEW-UHFFFAOYSA-N 2-vinylpyridine Chemical compound C=CC1=CC=CC=N1 KGIGUEBEKRSTEW-UHFFFAOYSA-N 0.000 claims description 24
- 239000013067 intermediate product Substances 0.000 claims description 24
- 125000000217 alkyl group Chemical group 0.000 claims description 22
- 239000003999 initiator Substances 0.000 claims description 21
- 238000000034 method Methods 0.000 claims description 21
- 238000007069 methylation reaction Methods 0.000 claims description 19
- 239000011812 mixed powder Substances 0.000 claims description 19
- 239000011267 electrode slurry Substances 0.000 claims description 16
- 239000011248 coating agent Substances 0.000 claims description 15
- 238000000576 coating method Methods 0.000 claims description 15
- 239000006258 conductive agent Substances 0.000 claims description 14
- 239000001257 hydrogen Substances 0.000 claims description 14
- 229910052739 hydrogen Inorganic materials 0.000 claims description 14
- 239000003960 organic solvent Substances 0.000 claims description 13
- 239000012336 iodinating agent Substances 0.000 claims description 12
- 239000013543 active substance Substances 0.000 claims description 10
- 238000006116 polymerization reaction Methods 0.000 claims description 10
- 239000003112 inhibitor Substances 0.000 claims description 9
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 8
- 125000003710 aryl alkyl group Chemical group 0.000 claims description 8
- 238000005349 anion exchange Methods 0.000 claims description 7
- 150000003839 salts Chemical class 0.000 claims description 7
- 150000002431 hydrogen Chemical class 0.000 claims description 6
- 239000012298 atmosphere Substances 0.000 claims description 5
- 239000003795 chemical substances by application Substances 0.000 claims description 5
- 230000014759 maintenance of location Effects 0.000 abstract description 18
- 239000000853 adhesive Substances 0.000 abstract description 15
- 230000001070 adhesive effect Effects 0.000 abstract description 15
- 239000007773 negative electrode material Substances 0.000 abstract description 10
- 239000007774 positive electrode material Substances 0.000 abstract description 9
- 230000005540 biological transmission Effects 0.000 abstract description 6
- 239000000463 material Substances 0.000 abstract description 6
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 26
- 229910021383 artificial graphite Inorganic materials 0.000 description 22
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 22
- 229910052744 lithium Inorganic materials 0.000 description 21
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 20
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 16
- 238000001035 drying Methods 0.000 description 16
- 239000002033 PVDF binder Substances 0.000 description 14
- 238000000498 ball milling Methods 0.000 description 14
- 238000012360 testing method Methods 0.000 description 14
- 239000011149 active material Substances 0.000 description 12
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 11
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 11
- 238000001291 vacuum drying Methods 0.000 description 11
- 238000001914 filtration Methods 0.000 description 10
- OZAIFHULBGXAKX-UHFFFAOYSA-N 2-(2-cyanopropan-2-yldiazenyl)-2-methylpropanenitrile Chemical compound N#CC(C)(C)N=NC(C)(C)C#N OZAIFHULBGXAKX-UHFFFAOYSA-N 0.000 description 9
- 229920003048 styrene butadiene rubber Polymers 0.000 description 9
- 150000001450 anions Chemical class 0.000 description 8
- 239000002184 metal Substances 0.000 description 8
- AZQWKYJCGOJGHM-UHFFFAOYSA-N 1,4-benzoquinone Chemical compound O=C1C=CC(=O)C=C1 AZQWKYJCGOJGHM-UHFFFAOYSA-N 0.000 description 7
- 239000002174 Styrene-butadiene Substances 0.000 description 7
- 229910052782 aluminium Inorganic materials 0.000 description 7
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical group [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 7
- 239000003792 electrolyte Substances 0.000 description 7
- 239000011888 foil Substances 0.000 description 7
- INQOMBQAUSQDDS-UHFFFAOYSA-N iodomethane Chemical compound IC INQOMBQAUSQDDS-UHFFFAOYSA-N 0.000 description 7
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 7
- 239000012299 nitrogen atmosphere Substances 0.000 description 7
- 239000007787 solid Substances 0.000 description 7
- WEVYAHXRMPXWCK-UHFFFAOYSA-N Acetonitrile Chemical compound CC#N WEVYAHXRMPXWCK-UHFFFAOYSA-N 0.000 description 6
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 6
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 6
- 239000002003 electrode paste Substances 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000002244 precipitate Substances 0.000 description 6
- 238000005096 rolling process Methods 0.000 description 5
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 4
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 4
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 4
- 239000006229 carbon black Substances 0.000 description 4
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 4
- 229910000625 lithium cobalt oxide Inorganic materials 0.000 description 4
- BFZPBUKRYWOWDV-UHFFFAOYSA-N lithium;oxido(oxo)cobalt Chemical compound [Li+].[O-][Co]=O BFZPBUKRYWOWDV-UHFFFAOYSA-N 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- QKHRGPYNTXRMSL-VOTSOKGWSA-N 4-[(e)-2-phenylethenyl]pyridine Chemical compound C=1C=CC=CC=1/C=C/C1=CC=NC=C1 QKHRGPYNTXRMSL-VOTSOKGWSA-N 0.000 description 3
- KFDVPJUYSDEJTH-UHFFFAOYSA-N 4-ethenylpyridine Chemical compound C=CC1=CC=NC=C1 KFDVPJUYSDEJTH-UHFFFAOYSA-N 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical group [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 3
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 239000004743 Polypropylene Substances 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 3
- 239000011889 copper foil Substances 0.000 description 3
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 3
- 230000005611 electricity Effects 0.000 description 3
- 239000011883 electrode binding agent Substances 0.000 description 3
- 239000000839 emulsion Substances 0.000 description 3
- 239000012982 microporous membrane Substances 0.000 description 3
- 238000011056 performance test Methods 0.000 description 3
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 3
- 229920001155 polypropylene Polymers 0.000 description 3
- 230000001376 precipitating effect Effects 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- 238000007581 slurry coating method Methods 0.000 description 3
- FVAUCKIRQBBSSJ-UHFFFAOYSA-M sodium iodide Chemical compound [Na+].[I-] FVAUCKIRQBBSSJ-UHFFFAOYSA-M 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- 238000010998 test method Methods 0.000 description 3
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 3
- 238000005979 thermal decomposition reaction Methods 0.000 description 3
- FRASJONUBLZVQX-UHFFFAOYSA-N 1,4-naphthoquinone Chemical compound C1=CC=C2C(=O)C=CC(=O)C2=C1 FRASJONUBLZVQX-UHFFFAOYSA-N 0.000 description 2
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 229910004764 HSV900 Inorganic materials 0.000 description 2
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 2
- 239000010405 anode material Substances 0.000 description 2
- 239000006256 anode slurry Substances 0.000 description 2
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 239000000543 intermediate Substances 0.000 description 2
- ZQMHJBXHRFJKOT-UHFFFAOYSA-N methyl 2-[(1-methoxy-2-methyl-1-oxopropan-2-yl)diazenyl]-2-methylpropanoate Chemical compound COC(=O)C(C)(C)N=NC(C)(C)C(=O)OC ZQMHJBXHRFJKOT-UHFFFAOYSA-N 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 2
- 239000002491 polymer binding agent Substances 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- YQMUORJJDBQCOV-UHFFFAOYSA-N $l^{1}-phosphanylmethane Chemical compound [P]C YQMUORJJDBQCOV-UHFFFAOYSA-N 0.000 description 1
- ZFPGARUNNKGOBB-UHFFFAOYSA-N 1-Ethyl-2-pyrrolidinone Chemical compound CCN1CCCC1=O ZFPGARUNNKGOBB-UHFFFAOYSA-N 0.000 description 1
- GPKIXZRJUHCCKX-UHFFFAOYSA-N 2-[(5-methyl-2-propan-2-ylphenoxy)methyl]oxirane Chemical compound CC(C)C1=CC=C(C)C=C1OCC1OC1 GPKIXZRJUHCCKX-UHFFFAOYSA-N 0.000 description 1
- VMWGBWNAHAUQIO-UHFFFAOYSA-N 2-ethenyl-6-methylpyridine Chemical compound CC1=CC=CC(C=C)=N1 VMWGBWNAHAUQIO-UHFFFAOYSA-N 0.000 description 1
- BRZOWWLQQFFSLC-UHFFFAOYSA-N 3-ethenyl-5-fluoropyridine Chemical compound FC1=CN=CC(C=C)=C1 BRZOWWLQQFFSLC-UHFFFAOYSA-N 0.000 description 1
- OMPJBNCRMGITSC-UHFFFAOYSA-N Benzoylperoxide Chemical compound C=1C=CC=CC=1C(=O)OOC(=O)C1=CC=CC=C1 OMPJBNCRMGITSC-UHFFFAOYSA-N 0.000 description 1
- BWGNESOTFCXPMA-UHFFFAOYSA-N Dihydrogen disulfide Chemical compound SS BWGNESOTFCXPMA-UHFFFAOYSA-N 0.000 description 1
- 229910004761 HSV 900 Inorganic materials 0.000 description 1
- 229910010707 LiFePO 4 Inorganic materials 0.000 description 1
- 229910013716 LiNi Inorganic materials 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 238000005411 Van der Waals force Methods 0.000 description 1
- 229910007717 ZnSnO Inorganic materials 0.000 description 1
- KFDQGLPGKXUTMZ-UHFFFAOYSA-N [Mn].[Co].[Ni] Chemical compound [Mn].[Co].[Ni] KFDQGLPGKXUTMZ-UHFFFAOYSA-N 0.000 description 1
- DPXJVFZANSGRMM-UHFFFAOYSA-N acetic acid;2,3,4,5,6-pentahydroxyhexanal;sodium Chemical compound [Na].CC(O)=O.OCC(O)C(O)C(O)C(O)C=O DPXJVFZANSGRMM-UHFFFAOYSA-N 0.000 description 1
- 239000006230 acetylene black Substances 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 239000006183 anode active material Substances 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 235000019400 benzoyl peroxide Nutrition 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 229910021393 carbon nanotube Inorganic materials 0.000 description 1
- 239000002041 carbon nanotube Substances 0.000 description 1
- 239000001768 carboxy methyl cellulose Substances 0.000 description 1
- 239000010406 cathode material Substances 0.000 description 1
- 239000012295 chemical reaction liquid Substances 0.000 description 1
- 230000001351 cycling effect Effects 0.000 description 1
- QHGJSLXSVXVKHZ-UHFFFAOYSA-N dilithium;dioxido(dioxo)manganese Chemical compound [Li+].[Li+].[O-][Mn]([O-])(=O)=O QHGJSLXSVXVKHZ-UHFFFAOYSA-N 0.000 description 1
- 238000006056 electrooxidation reaction Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 125000000524 functional group Chemical group 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 230000026045 iodination Effects 0.000 description 1
- 238000006192 iodination reaction Methods 0.000 description 1
- 229920000831 ionic polymer Polymers 0.000 description 1
- 230000002427 irreversible effect Effects 0.000 description 1
- 239000003273 ketjen black Substances 0.000 description 1
- 239000011572 manganese Substances 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- RHFUXPCCELGMFC-UHFFFAOYSA-N n-(6-cyano-3-hydroxy-2,2-dimethyl-3,4-dihydrochromen-4-yl)-n-phenylmethoxyacetamide Chemical class OC1C(C)(C)OC2=CC=C(C#N)C=C2C1N(C(=O)C)OCC1=CC=CC=C1 RHFUXPCCELGMFC-UHFFFAOYSA-N 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 125000002467 phosphate group Chemical group [H]OP(=O)(O[H])O[*] 0.000 description 1
- WKFBZNUBXWCCHG-UHFFFAOYSA-N phosphorus trifluoride Chemical compound FP(F)F WKFBZNUBXWCCHG-UHFFFAOYSA-N 0.000 description 1
- FFUQCRZBKUBHQT-UHFFFAOYSA-N phosphoryl fluoride Chemical compound FP(F)(F)=O FFUQCRZBKUBHQT-UHFFFAOYSA-N 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 229920005596 polymer binder Polymers 0.000 description 1
- JLKDVMWYMMLWTI-UHFFFAOYSA-M potassium iodate Chemical compound [K+].[O-]I(=O)=O JLKDVMWYMMLWTI-UHFFFAOYSA-M 0.000 description 1
- 239000001230 potassium iodate Substances 0.000 description 1
- 235000006666 potassium iodate Nutrition 0.000 description 1
- 229940093930 potassium iodate Drugs 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 239000008213 purified water Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 235000019812 sodium carboxymethyl cellulose Nutrition 0.000 description 1
- 229920001027 sodium carboxymethylcellulose Polymers 0.000 description 1
- BFDWBSRJQZPEEB-UHFFFAOYSA-L sodium fluorophosphate Chemical compound [Na+].[Na+].[O-]P([O-])(F)=O BFDWBSRJQZPEEB-UHFFFAOYSA-L 0.000 description 1
- 235000009518 sodium iodide Nutrition 0.000 description 1
- UGNWTBMOAKPKBL-UHFFFAOYSA-N tetrachloro-1,4-benzoquinone Chemical compound ClC1=C(Cl)C(=O)C(Cl)=C(Cl)C1=O UGNWTBMOAKPKBL-UHFFFAOYSA-N 0.000 description 1
- 238000002411 thermogravimetry Methods 0.000 description 1
- ALRFTTOJSPMYSY-UHFFFAOYSA-N tin disulfide Chemical compound S=[Sn]=S ALRFTTOJSPMYSY-UHFFFAOYSA-N 0.000 description 1
- BNEMLSQAJOPTGK-UHFFFAOYSA-N zinc;dioxido(oxo)tin Chemical compound [Zn+2].[O-][Sn]([O-])=O BNEMLSQAJOPTGK-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention provides an ionic copolymer binder, a preparation method and application thereof, and belongs to the technical field of lithium ion batteries. The ionic copolymer binder provided by the invention is a copolymer of vinyl pyridine phosphate containing hexafluorophosphate radical and polyethylene glycol acrylic ester, and when the copolymer is used for preparing a positive electrode plate of a lithium ion battery and a negative electrode plate of the lithium ion battery, the coulomb force between hexafluorophosphate radical in the ionic copolymer binder and a positive electrode or negative electrode active material can enhance the cohesiveness between materials; polyethylene glycol acrylic ester can improve the flexibility of the adhesive on one hand, soften the pole piece, and improve the ion transmission performance of an interface on the other hand, so that the lithium ion battery assembled by using the adhesive has higher specific capacity, capacity retention rate and cycle stability.
Description
Technical Field
The invention relates to the technical field of lithium ion batteries, in particular to an ionic copolymer binder, a preparation method and application thereof.
Background
The lithium ion battery has the advantages of high capacity density, long cycle life, environmental protection, wide use temperature range, high safety performance and the like, and is widely applied to the fields of mobile electronic equipment, electric automobiles and the like. The lithium ion battery mainly comprises a positive electrode, a diaphragm, a negative electrode, electrolyte and a battery shell, wherein the bonding strength between a positive electrode material and a negative electrode material and between a conductive agent and a current collector has a non-negligible influence on the cycling stability of the battery; also, when the electrochemical stability of the binder is not good, some functional groups of the binder may undergo irreversible chemical reaction with lithium ions during the electrochemical process of the electrode, thereby resulting in a decrease in the reversible capacity of the battery. Therefore, the high-performance binder is an effective means for solving the problems of pulverization of the active material, falling off of the active material from the current collector and the like and improving the circularity of the lithium ion battery.
Currently, there are many types of lithium ion battery binders, and there are common polyvinylidene fluoride (PVDF) and styrene-butadiene copolymer (SBR) emulsions, etc. As a commercialized battery positive electrode binder, PVDF is favored because of its strong electrochemical corrosion resistance and a wider electrochemical window, however, PVDF can only be combined with active materials by means of van der waals force, and can cause the falling-off between an electrode and a current collector in the cycle, which cannot meet the requirements of a high-performance battery; in addition, the PVDF of lithium level has larger supply gap and is expensive. The unsaturated bonds of SBR are easily oxidized at a high potential, so SBR emulsion is mainly used as a negative electrode binder. Therefore, the conventional lithium ion battery adhesive has the problems that the adhesive is poor in adhesion with an electrode plate and the anode and cathode adhesives cannot be used generally.
Various researches on positive and negative electrode binders of lithium ion batteries are disclosed, for example, chinese patent CN 111180733A discloses a binder containing ethylene carbonate, which endows a polymer binder with certain elasticity to enable an electrode structure to be more stable, but the electrode pole piece prepared by the binder is still poor in cohesiveness, the peeling strength between a dry slurry coating on the surface of a current collector in the pole piece and the current collector is low, and further the capacity retention rate of a battery assembled by the electrode pole pieces is lower than 70%.
Therefore, it is needed to provide a binder which can be used for both positive and negative electrodes in a common way, has good binding property and good battery cycle performance, so that the lithium ion battery has higher specific capacity, capacity retention rate and cycle stability.
Disclosure of Invention
The invention aims to provide an ionic copolymer binder, a preparation method and application thereof, and the ionic copolymer binder provided by the invention has excellent binding performance, can be used for both positive and negative poles, and has higher specific capacity, capacity retention rate and cycle stability.
In order to achieve the above object, the present invention provides the following technical solutions:
the invention provides an ionic copolymer binder which is characterized by having a chemical structure shown in a formula I:
in the formula I, R 1 Is alkyl, R 2 Is hydrogen, alkyl or aralkyl, R 3 Is hydrogen or alkyl, n=4 to 40, m=50 to 900, q=0 to 1200;
the invention provides a preparation method of the ionic copolymer binder, which comprises the following steps: mixing vinylpyridine phosphate, polyethylene glycol acrylic ester, an initiator and a solvent in inert atmosphere, and then carrying out free radical polymerization reaction to obtain an ionic copolymer binder;
The vinyl pyridine phosphate has a chemical structure shown in a formula II, and the polyethylene glycol acrylate has a chemical structure shown in a formula III:
in the formula II, R 1 Is alkyl, R 2 Is hydrogen, alkyl or aralkyl;
in the formula III, R 3 Is hydrogen or alkyl, and n is 4-40.
Preferably, the preparation method of the vinylpyridine phosphate comprises the following steps:
(1) Mixing vinyl pyridine, an iodizing agent, a polymerization inhibitor and a solvent for methylation reaction to obtain an intermediate product;
(2) And (3) mixing the intermediate product obtained in the step (1) with fluorophosphite to carry out negative ion replacement reaction to obtain the vinylpyridine phosphate.
Preferably, the ratio of the amounts of vinylpyridine, iodinating agent and fluorophosphoric salt in step (1) is (0.1-0.3): 0.2-0.4): 1.
Preferably, the temperature of the methylation reaction in the step (1) and the temperature of the anion exchange reaction in the step (2) are independently 10-45 ℃; the time of methylation reaction and the time of anion exchange reaction are independently 1-12 h.
Preferably, the ratio of the amounts of the substances of the vinylpyridine phosphate and the polyethylene glycol acrylate is 1 (0.3-1.1).
Preferably, the temperature of the free radical polymerization reaction is 45-80 ℃; the time of the free radical polymerization reaction is 6-24 h.
The invention also provides the application of the ionic copolymer binder in the technical scheme or the ionic copolymer binder prepared by the preparation method in the technical scheme in the electrode plate of the lithium ion battery.
Preferably, the preparation method of the lithium ion battery electrode plate comprises the following steps:
1) Dissolving an ionic copolymer binder in an organic solvent to obtain a binder solution;
2) Mixing an active substance and a conductive agent to obtain mixed powder;
3) Mixing the binder solution obtained in the step 1), the mixed powder obtained in the step 2) and an organic solvent to obtain electrode slurry;
4) Coating the electrode slurry obtained in the step 3) on a current collector to obtain a positive plate of the lithium ion battery;
the step 1) and the step 2) are not in sequence.
Preferably, the electrode plate of the lithium ion battery is a positive electrode plate or a negative electrode plate.
The ionic copolymer binder provided by the invention is a copolymer of vinyl pyridine phosphate containing hexafluorophosphate radical and polyethylene glycol acrylic ester, and when the copolymer is used for preparing a positive electrode plate of a lithium ion battery and a negative electrode plate of the lithium ion battery, the coulomb force between hexafluorophosphate radical in the ionic copolymer binder and a positive electrode or negative electrode active material can enhance the cohesiveness between materials; polyethylene glycol acrylic ester can improve the flexibility of the adhesive on one hand, soften the pole piece, and improve the ion transmission performance of an interface on the other hand, so that the lithium ion battery assembled by using the adhesive has higher specific capacity, capacity retention rate and cycle stability. The results of the examples show that the ionic copolymer binder provided by the invention has a molecular weight of 1.4X10 5 ～1.7×10 5 In Da, far below the commercial PVDF molecular weights, for example PVDF HSV900 (molecular weight 6.0X10) 5 Da), has lower viscosity, and is easier to coat; the peel strength of the surface coating of the positive plate of the lithium ion battery prepared by the ionic copolymer binder is 26.1-27.8N cm -1 The method comprises the steps of carrying out a first treatment on the surface of the The initial discharge specific capacity of the lithium cobalt oxide/metal lithium battery assembled by the positive electrode plate of the lithium ion battery is 136.7-140.8 mAh.g -1 The specific discharge capacity after 500 cycles at a current density of 1C is 115.9-125.4 mAh.g -1 The capacity retention rate is 82.31-88.81%; the peel strength of the surface coating of the negative electrode plate of the lithium ion battery prepared by the ionic copolymer binder is 103-119N cm -1 The method comprises the steps of carrying out a first treatment on the surface of the The initial discharge specific capacity of the lithium cobalt oxide/metal lithium battery assembled by the lithium ion battery negative electrode plate is 247.8-268.3 mAh.g -1 The specific discharge capacity after 500 cycles at a current density of 1C is 219.5-239.7 mAh.g -1 The capacity retention rate was 87.21 to 89.34%.
Drawings
FIG. 1 is a graph showing the long-cycle charge and discharge performance test of a lithium iron phosphate/lithium metal battery with a positive electrode plate assembled at C3 in test example 2 of the present invention under the magnification conditions of 25℃and a cut-off voltage of 2.5 to 4.2V and 1C;
Fig. 2 is a long-cycle charge-discharge performance test curve of the lithium iron phosphate/lithium metal battery assembled with the positive electrode sheet of the test example 2 according to the present invention under the conditions of 25 ℃ and cut-off voltages of 2.5 to 4.2V and multiplying powers of 0.5C, 1C, 2C and 3C.
Detailed Description
The invention provides an ionic copolymer binder which is characterized by having a chemical structure shown in a formula I:
in the present invention, R in the formula I 1 Is alkyl, R 2 Is hydrogen, alkyl or aralkyl, R 3 Is hydrogen or alkyl, n=4 to 40, m=50 to 900, q=0 to 1200; the alkyl group is preferably methyl or ethyl; the aralkyl group is preferably a phenyl group; m is preferably 250 to 500; q is preferably 220 to 1000. The ionic copolymer binder with the structure shown in the formula I can enable the binder to have good cohesiveness, and when the ionic copolymer binder is used for preparing the positive pole piece of the lithium ion battery and the negative pole piece of the lithium ion battery, the coulomb force between hexafluorophosphate radical in the ionic copolymer binder and the positive or negative active material can enhance the cohesiveness between the materials; polyethylene glycol acrylic ester can improve the flexibility of the adhesive on one hand, soften the pole piece, and improve the ion transmission performance of an interface on the other hand, so that the lithium ion battery assembled by using the adhesive has higher specific capacity, capacity retention rate and cycle stability.
The invention provides a preparation method of the ionic copolymer binder, which comprises the following steps: and mixing the vinylpyridine phosphate, the polyethylene glycol acrylic ester, the initiator and the solvent in inert atmosphere, and then carrying out free radical polymerization reaction to obtain the ionic copolymer binder.
In the present invention, the gas of the inert atmosphere is preferably nitrogen or argon. In the present invention, the inert atmosphere can avoid the interference of air with the radical polymerization reaction.
In the present invention, the vinylpyridine phosphate has a chemical structure as shown in formula II:
in the present invention, R in the formula II 1 Is alkyl, R 2 Is hydrogen, alkyl or aralkyl; the alkyl group is preferably methyl or ethyl; the aralkyl group is preferably a phenyl group. In the invention, the vinyl pyridine phosphate contains hexafluorophosphate radical when in the structure, so that the prepared ionic copolymer binder can enhance the cohesiveness between materials when being used for preparing positive pole pieces of lithium ion batteries and negative pole pieces of lithium ion batteries.
In the present invention, the preparation method of the vinylpyridine phosphate preferably comprises the following steps:
(1) Mixing vinyl pyridine, an iodizing agent, a polymerization inhibitor and a solvent for methylation reaction to obtain an intermediate product;
(2) And (3) mixing the intermediate product obtained in the step (1) with fluorophosphite to carry out negative ion replacement reaction to obtain the vinylpyridine phosphate.
In the invention, preferably, the vinyl pyridine, the iodizing agent, the polymerization inhibitor and the solvent are mixed for methylation reaction to obtain an intermediate product.
In the present invention, the vinylpyridine is preferably one or more of 4-vinylpyridine, 2-vinylpyridine, 4-styrylpyridine, pyridylmethacrylate disulfide, 3-fluoro-5-vinylpyridine and 2-methyl-6-vinylpyridine. The present invention selects the above-mentioned class of vinylpyridines, which are utilized to promote the formation of intermediates in methylation reactions.
In the present invention, the iodinating agent preferably includes one or more of methyl iodide, potassium iodate, sodium iodide and potassium dithioiodide. The present invention can form a structure having an alkyl group on the structure of an intermediate product by iodination of an iodinating agent by selecting the above-mentioned kind of iodinating agent.
In the present invention, the polymerization inhibitor is preferably one or more of benzoquinone, tetrachlorobenzoquinone, and 1, 4-naphthoquinone. The invention prevents free radical polymerization reaction by adding the polymerization inhibitor, and retains double bonds of vinyl pyridine.
In the present invention, the mass of the polymerization inhibitor is preferably 0.01 to 0.5% by mass of vinylpyridine, more preferably 0.05 to 0.2%. The invention is more beneficial to controlling the reaction degree of the free radical polymerization reaction by controlling the addition amount of the polymerization inhibitor to be in the range.
In the present invention, the solvent preferably includes one or more of N-methylpyrrolidone, N-ethylpyrrolidone, N-dimethylformamide, tetrahydrofuran, methylene chloride, toluene, and chloroform. The solvent of the above type is selected to have excellent compatibility with each raw material, thereby being more favorable for the methylation reaction to be fully carried out. The amount of the solvent used in the present invention is not particularly limited, and the total mass concentration of the vinylpyridine, the iodinating agent and the fluorophosphoric acid salt may be adjusted as needed to be within the range of 10 to 35%.
The method for mixing the vinyl pyridine, the iodinating agent, the polymerization inhibitor and the solvent is not particularly limited, and the components can be uniformly mixed by adopting a mixing method well known to those skilled in the art.
In the present invention, the temperature of the methylation reaction is preferably 10 to 45 ℃, more preferably 25 to 30 ℃; the time for the methylation reaction is preferably 1 to 12 hours, more preferably 6 to 10 hours. The invention can avoid the polymerization of vinyl pyridine by controlling the temperature and time of methylation reaction, and is more beneficial to forming intermediate products. The apparatus for the methylation reaction is not particularly limited, and a reaction apparatus well known to those skilled in the art may be used. In the present invention, the apparatus for methylation reaction is preferably a reaction vessel.
After the intermediate product is obtained, the invention preferably mixes the intermediate product with fluorophosphite to carry out anion replacement reaction to obtain the vinylpyridine phosphate.
In the present invention, the fluorophosphorus salt preferably includes one or more of ammonium hexafluorophosphate, sodium fluorophosphate, phosphorus trifluoride, methylphosphorus and phosphorus oxyfluoride. The invention combines phosphate groups on intermediate product molecules by adopting the fluorophosphorus salt of the type, thereby forming the vinylpyridine phosphate containing hexafluorophosphate ionic groups.
In the present invention, the ratio of the amounts of the substances of the vinylpyridine, the iodinating agent and the fluorophosphoric salt is preferably (0.1 to 0.3): 0.2 to 0.4): 1, more preferably (0.2 to 0.3): 0.3 to 0.4): 1. In the present invention, when the ratio of the amounts of the substances of the vinylpyridine, the iodinating agent and the fluorophosphoric salt is in the above-described range, the respective components can be sufficiently reacted.
The method of mixing the intermediate product with the fluorophosphoric salt is not particularly limited in the present invention, and the above components can be uniformly mixed by a mixing method well known to those skilled in the art.
In the present invention, the temperature of the anion exchange reaction is preferably 10 to 45 ℃, more preferably 25 to 30 ℃; the time for the anion exchange reaction is preferably 1 to 12 hours, more preferably 6 to 10 hours. The invention can avoid side reaction by controlling the temperature and time of the anion replacement reaction, and can fully carry out the anion replacement reaction, thereby being more beneficial to forming the vinylpyridine phosphate. The apparatus for the anion exchange reaction is not particularly limited, and a reaction apparatus known to those skilled in the art may be used. In the present invention, the apparatus for methylation reaction is preferably a reaction vessel.
After the anion replacement reaction, the system obtained by the anion replacement reaction is preferably filtered and dried in sequence to obtain the vinylpyridine phosphate. The method of the present invention is not particularly limited, and the method of filtration and drying known to those skilled in the art may be used. In the present invention, the drying is preferably vacuum drying; the temperature of the vacuum drying is preferably 30-60 ℃, more preferably 50-60 ℃; the time for the vacuum drying is preferably 1 to 24 hours, more preferably 12 to 24 hours.
In the present invention, the polyethylene glycol acrylate has a chemical structure as shown in formula III:
in the present invention, R in the formula III 3 Is hydrogen or alkyl, n is 4-40; the alkyl group is preferably methyl, and the n is preferably 10 to 40.
In the invention, when the polyethylene glycol acrylate has the structure, on one hand, the flexibility of the binder can be improved, the pole piece is softened, and on the other hand, the ion transmission performance of the interface can be improved, so that the lithium ion battery assembled by using the binder has higher specific capacity, capacity retention rate and cycle stability.
In the present invention, the ratio of the amounts of the vinyl pyridine phosphate and polyethylene glycol acrylate is preferably 1 (0.3 to 1.1), more preferably 1 (0.5 to 0.8). In the present invention, when the ratio of the amounts of the vinyl pyridine phosphate and the polyethylene glycol acrylate is in the above range, radical polymerization can be sufficiently performed, and the adhesive can have better adhesive properties.
In the present invention, the initiator is preferably one or more of azobisisobutyronitrile, azobicyclohexylcarbonitrile, dimethyl azobisisobutyrate and dibenzoyl peroxide, more preferably azobicyclobutyronitrile, azobicyclohexylcarbonitrile or dimethyl azobisisobutyrate. In the present invention, the initiator is capable of initiating the free radical polymerization of the monomer.
In the present invention, the mass of the initiator is preferably 0.1 to 1%, more preferably 0.1 to 0.5% of the sum of the mass of the vinylpyridine phosphate and the polyethylene glycol acrylate. In the present invention, the control of the amount of the initiator within the above range can promote the radical polymerization reaction to proceed sufficiently.
In the present invention, the solvent preferably includes one or more of water, diethyl ether, acetonitrile, toluene, acetone, N-methylpyrrolidone, N-dimethylformamide, tetrahydrofuran, methylene chloride, and chloroform. The solvent has good compatibility with all raw materials, thereby ensuring that the free radical polymerization reaction is fully carried out.
In the present invention, the mass of the solvent is preferably such that the total mass concentration of the vinylpyridine phosphate and polyethylene glycol acrylate is maintained at 10 to 20%, more preferably 15 to 20%. In the present invention, the solvent is more advantageous in sufficiently proceeding the radical polymerization reaction in the above-mentioned amount range.
The method for mixing the vinylpyridine phosphate, the polyethylene glycol acrylate, the initiator and the solvent is not particularly limited, and the components can be uniformly mixed by adopting a mixing method well known to a person skilled in the art.
In the present invention, the temperature of the radical polymerization is preferably 45 to 80 ℃, more preferably 60 to 70 ℃; the time of the radical polymerization is preferably 6 to 24 hours, more preferably 12 to 24 hours. In the present invention, when the temperature and time of the radical polymerization reaction are within the above ranges, the radical polymerization reaction can be sufficiently performed.
After the free radical polymerization reaction is completed, the product of the free radical polymerization reaction is preferably subjected to precipitation, filtration and drying in sequence to obtain the ionic copolymer binder.
In the present invention, the method of precipitation is preferably to add the product of the radical polymerization reaction to a precipitating agent. In the present invention, the precipitant preferably includes one or more of diethyl ether, petroleum ether, n-hexane and methanol. The invention adopts the precipitant to separate the ionic polymer binder from the reaction liquid. The amount of the precipitant is not particularly limited, and the precipitant can be adjusted according to conventional operation, so that the product after the free radical polymerization reaction can be sufficiently precipitated.
The operation of the filtration is not particularly limited in the present invention, and may be an operation well known to those skilled in the art.
In the present invention, drying is preferably vacuum drying; the temperature of the vacuum drying is preferably 30-60 ℃, more preferably 50-60 ℃; the time for the vacuum drying is preferably 1 to 24 hours, more preferably 12 to 24 hours.
According to the preparation method provided by the invention, the vinyl pyridine phosphate and polyethylene glycol acrylic ester are subjected to free radical polymerization under the action of the initiator, so that hexafluorophosphate ions are introduced into the ionic copolymer binder.
The invention also provides the application of the ionic copolymer binder in the lithium ion battery electrode plate or the ionic copolymer binder prepared by the preparation method in the technical scheme.
In the invention, the preparation method of the positive plate of the lithium ion battery preferably comprises the following steps:
1) Dissolving an ionic copolymer binder in an organic solvent to obtain a binder solution;
2) Mixing an active substance and a conductive agent to obtain mixed powder;
3) Mixing the binder solution obtained in the step 1), the mixed powder obtained in the step 2) and an organic solvent to obtain electrode slurry;
4) And coating the electrode slurry obtained in the step 3) on a current collector to obtain the positive plate of the lithium ion battery.
In the present invention, the ionic copolymer binder is preferably dissolved in an organic solvent to obtain a binder solution.
In the present invention, the organic solvent is preferably one or more of N-methylpyrrolidone, tetrahydrofuran and acetonitrile. The organic solvent has excellent solubility to the ionic copolymer binder.
The amount of the organic solvent used in the present invention is not particularly limited, and the viscosity of the binder solution may be in the range of 0.2 to 20pa·s, preferably 10 to 15pa·s. In the present invention, when the viscosity of the binder solution is in the above range, the ionic copolymer binder can be sufficiently dissolved, and it is advantageous to control the viscosity of the slurry to be suitable.
The present invention preferably mixes the active material and the conductive agent to obtain a mixed powder.
In the present invention, the active material preferably includes a positive electrode active material or a negative electrode active material, and when the active material is a positive electrode active material, a positive electrode sheet of a lithium ion battery is obtained; when the active material is a negative active material, the obtained lithium ion battery negative electrode plate is obtained.
In the present invention, the positive electrode active material preferably includes lithium iron phosphate (LiFePO 4 ) Lithium cobalt oxide (LiCoO) 2 ) Lithium manganate (LiMn) 2 O 4 ) Nickel cobalt manganese (LiNi) 0.8 Co 0.1 Mn 0.1 O 2 ) Or lithium titanate (Li) 4 Ti 5 O 12 ). The invention can lead the anode material to have good electrochemical performance by adopting the active substances.
In the present invention, the negative electrode active material preferably includes artificial graphite, silicon carbide (SiC), zinc stannate (ZnSnO) 3 ) Tricobalt tetraoxide (Co) 3 O 4 ) Or tin disulfide (SnS) 2 ). The invention can make the lithium ion battery have excellent electrochemical performance by adopting the negative electrode active material.
In the present invention, the conductive agent preferably includes one or more of superconducting carbon, carbon nanotubes, acetylene black and ketjen black. The invention can make the anode and cathode materials have good electrochemical performance by selecting the above-mentioned kind of conductive agent.
In the present invention, the mass ratio of the active material, the conductive agent and the ionic copolymer binder is preferably (60-98): 1-20, more preferably (70-85): 5-15. The lithium ion battery can have good electrochemical performance by controlling the mass ratio of the active substance, the conductive agent and the ionic copolymer binder within the range.
In the present invention, the method of mixing the active material and the conductive agent preferably includes: the active material and the conductive agent are ball milled for 1 to 4 hours at the room temperature at the rotation speed of 600 to 1200rpm, preferably for 2 to 3 hours at the rotation speed of 800 to 1000 rpm. In the present invention, the active material and the conductive agent can be uniformly mixed by the above-mentioned mixing method.
After the binder solution and the mixed powder are obtained, the binder solution, the mixed powder and the organic solvent are preferably mixed to obtain the electrode slurry.
In the present invention, the method of mixing the binder solution, the mixed powder, and the organic solvent preferably includes: ball milling the mixed powder and the binder solution for 1-10 h at 600-1200 rpm, preferably at 800-1000 rpm for 5-8 h; then adding an organic solvent for continuous ball milling for 1-4 hours, preferably for 2-3 hours, to obtain the electrode slurry. The invention is more favorable for fully and uniformly mixing the raw materials by adopting the mixing operation and controlling the parameters thereof in the range.
After electrode slurry is obtained, the electrode slurry is coated on a current collector to obtain the electrode plate of the lithium ion battery.
In the present invention, when the electrode paste is a positive electrode paste, the current collector is preferably aluminum foil. The size of the aluminum foil is not particularly limited, and the aluminum foil can be adjusted according to actual needs.
In the present invention, when the electrode paste is a negative electrode paste, the current collector is preferably copper foil. The size of the aluminum foil is not particularly limited, and the aluminum foil can be adjusted according to actual needs.
In the present invention, the coating apparatus is preferably a knife coater. The type of the blade coater is not particularly limited, and the blade coater may be any type of blade coater known to those skilled in the art.
The thickness of the electrode paste coating is not particularly limited, and the electrode paste coating can be adjusted according to the conventional requirements. In the present invention, the thickness of the coating is preferably 60 to 300 μm.
After the coating is finished, the product obtained by the coating is dried, rolled and cut into pieces in sequence to obtain the electrode plate of the lithium ion battery.
In the present invention, the drying preferably includes normal pressure drying and vacuum drying which are sequentially performed; the temperature of the normal pressure drying is preferably 40-60 ℃; the time of normal pressure drying is preferably 6-24 hours; the temperature of the vacuum drying is preferably 80 ℃; the time of the vacuum drying is preferably 6 to 24 hours.
The operation of the rolling and cutting is not particularly limited in the present invention, and may be an operation well known to those skilled in the art.
According to the invention, the ionic copolymer binder is used as the binder of the positive electrode plate of the lithium ion battery and the negative electrode plate of the lithium ion battery, and as the ionic copolymer binder has excellent cohesiveness, when the ionic copolymer binder is used for preparing the positive electrode plate of the lithium ion battery and the negative electrode plate of the lithium ion battery, the coulomb force between hexafluorophosphate radical in the ionic copolymer binder and the positive electrode or the negative electrode active material can enhance the cohesiveness between the materials; polyethylene glycol acrylic ester can improve the flexibility of the adhesive on one hand, soften the pole piece, and improve the ion transmission performance of an interface on the other hand, so that the lithium ion battery assembled by using the adhesive has higher specific capacity, capacity retention rate and cycle stability.
The technical solutions of the present invention will be clearly and completely described in the following in connection with the embodiments of the present invention. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Example 1
An ionic copolymer binder having the chemical structure:
the preparation method of the ionic copolymer binder comprises the following steps: mixing 200g of vinylpyridine phosphate, 400g of polyethylene glycol acrylate, 0.60g of initiator (azodiisobutyronitrile) and 5400g of solvent (N-methylpyrrolidone) in a reaction kettle under nitrogen atmosphere, performing free radical polymerization reaction for 7h at 70 ℃, precipitating the intermediate product into 40000g of diethyl ether, filtering, and vacuum-drying the precipitate at 40 ℃ for 12h to obtain 484g of ionic copolymer binder which is named as A1;
wherein: the ratio of the amounts of the substances of the vinylpyridine phosphate and the polyethylene glycol acrylate is 1:1.05; the mass of the initiator accounts for 0.1 percent of the sum of the mass of the vinylpyridine phosphate and the polyethylene glycol acrylate; the mass of the solvent enables the mass concentration of the vinylpyridine phosphate and the polyethylene glycol acrylate to be 10%;
The vinyl pyridine phosphate is 4-vinyl-N-methyl pyridine quaternary ammonium hexafluorophosphate, and the structural formula is shown in formula II:
in the formula II, R 1 Is methyl, R 2 Is hydrogen;
the preparation method of the vinylpyridine phosphate comprises the following steps:
(1) 200g of 4-vinylpyridine, 332g of methyl iodide and 0.30g of benzoquinone are dissolved in 4000g of methylene dichloride, and the mixture is stirred for 6 hours at 25 ℃ to carry out methylation reaction to obtain an intermediate product;
(2) Mixing the intermediate product obtained in the step (1) with 1297g of ammonium hexafluorophosphate, stirring for 8 hours at 25 ℃, carrying out anion replacement reaction, and then filtering to obtain a white solid; the white solid was dried under vacuum at 60℃for 12h to give 498g of 4-vinyl-N-methylpyridine quaternary ammonium hexafluorophosphate; wherein: the ratio of the amounts of the 4-vinylpyridine, methyl iodide and ammonium hexafluorophosphate species in step (1) to those in step (2) is 0.24:0.29:1; the mass of benzoquinone is 0.15% of the mass of vinyl pyridine; the addition of methylene dichloride enables the total mass concentration of the vinyl pyridine, the iodinating agent and the fluorophosphite to be 31.4%;
the molecular weight of polyethylene glycol acrylate is 500Da, and the structural formula is shown in formula III:
in the formula III, R 3 Methyl and n is 9.
Example 2
An ionic copolymer binder having the chemical structure:
The preparation method of the ionic copolymer binder comprises the following steps: under nitrogen atmosphere, 240g of vinylpyridine phosphate, 360g of polyethylene glycol acrylate, 0.60g of initiator (azodiisobutyronitrile) and 5400g of solvent (N-methylpyrrolidone) are mixed in a reaction kettle, then free radical polymerization reaction is carried out for 7h at 70 ℃, the intermediate product is precipitated into 40000g of diethyl ether, filtration is carried out, and the precipitate is dried in vacuum at 40 ℃ for 12h, thus 486g of ionic copolymer binder which is named as A2 is obtained;
wherein: vinylpyridine phosphate and polyethylene glycol acrylate are the same as in example 1; the ratio of the amounts of the substances of the vinylpyridine phosphate and the polyethylene glycol acrylate is 1:0.79; the mass of the initiator accounts for 0.1 percent of the sum of the mass of the vinylpyridine phosphate and the polyethylene glycol acrylate; the mass of the solvent enables the mass concentration of the vinylpyridine phosphate and the polyethylene glycol acrylate to be 10%.
Example 3
An ionic copolymer binder having the chemical structure:
the preparation method of the ionic copolymer binder comprises the following steps: mixing 300g of vinylpyridine phosphate, 300g of polyethylene glycol acrylate, 0.60g of initiator (azodiisobutyronitrile) and 5400g of solvent (N-methylpyrrolidone) in a reaction kettle under nitrogen atmosphere, performing free radical polymerization reaction for 7h at 70 ℃, precipitating the intermediate product into 40000g of diethyl ether, filtering, and vacuum-drying the precipitate at 40 ℃ for 12h to obtain 492g of ionic copolymer binder which is named as A3;
Wherein: vinylpyridine phosphate and polyethylene glycol acrylate are the same as in example 1; the ratio of the amounts of the substances of the vinylpyridine phosphate and the polyethylene glycol acrylate is 1:0.53; the mass of the initiator accounts for 0.1 percent of the sum of the mass of the vinylpyridine phosphate and the polyethylene glycol acrylate; the mass of the solvent enables the mass concentration of the vinylpyridine phosphate and the polyethylene glycol acrylate to be 10%.
Example 4
An ionic copolymer binder having the chemical structure:
the preparation method of the ionic copolymer binder comprises the following steps: under nitrogen atmosphere, 360g of vinylpyridine phosphate, 240g of polyethylene glycol acrylate, 0.60g of initiator (azodiisobutyronitrile) and 5400g of solvent (N-methylpyrrolidone) are mixed in a reaction kettle, then free radical polymerization reaction is carried out for 7h at 70 ℃, the intermediate product is precipitated into 40000g of diethyl ether, filtration is carried out, and the precipitate is dried in vacuum at 40 ℃ for 12h, thus obtaining 489g of ionic copolymer binder which is named as A4;
wherein: vinylpyridine phosphate and polyethylene glycol acrylate are the same as in example 1; the ratio of the amounts of the substances of the vinylpyridine phosphate and the polyethylene glycol acrylate is 1:0.35; the mass of the initiator accounts for 0.1 percent of the sum of the mass of the vinylpyridine phosphate and the polyethylene glycol acrylate; the mass of the solvent enables the mass concentration of the vinylpyridine phosphate and the polyethylene glycol acrylate to be 10%.
Example 5
An ionic copolymer binder having the chemical structure:
the preparation method of the ionic copolymer binder comprises the following steps: after 300g of vinylpyridine phosphate (4-styryl-N-methylpyridine quaternary ammonium hexafluorophosphate), 300g of polyethylene glycol acrylate, 0.60g of initiator (azobisisobutyronitrile) and 5400g of solvent (N-methylpyrrolidone) were mixed in a reaction kettle under a nitrogen atmosphere, radical polymerization was performed at 70℃for 7 hours, the above intermediate was precipitated into 40000g of diethyl ether, filtered, and the precipitate was dried under vacuum at 40℃for 12 hours to give 496g of an ionic copolymer binder designated A5;
wherein: polyethylene glycol acrylate was the same as in example 1; the ratio of the amounts of the substances of the vinylpyridine phosphate and the polyethylene glycol acrylate is 1:0.69; the mass of the initiator accounts for 0.1 percent of the sum of the mass of the vinylpyridine phosphate and the polyethylene glycol acrylate; the mass of the solvent enables the mass concentration of the vinylpyridine phosphate and the polyethylene glycol acrylate to be 10%;
the structural formula of the 4-styryl-N-methylpyridine quaternary ammonium hexafluorophosphate is as follows:
wherein R is 1 Is methyl, R 2 Is phenyl;
the preparation method of the 4-styryl-N-methylpyridine quaternary ammonium hexafluorophosphate comprises the following steps:
(1) 230g of 4-styrylpyridine, 221g of methyl iodide and 0.30g of benzoquinone are dissolved in 4000g of methylene dichloride, and the mixture is stirred for 6 hours at 25 ℃ to carry out methylation reaction to obtain an intermediate product;
(2) Mixing the intermediate product obtained in the step (1) with 863g of ammonium hexafluorophosphate, stirring for 8 hours at 25 ℃, carrying out anion replacement reaction, and then filtering to obtain a white solid; the white solid was dried under vacuum at 60℃for 12h to give 425g of 4-styryl-N-methylpyridine quaternary ammonium hexafluorophosphate; wherein: the ratio of the amounts of the substances of 4-styrylpyridine, methyl iodide and ammonium hexafluorophosphate in step (1) to those of step (2) is 0.24:0.29:1; the mass of benzoquinone is 0.13% of the mass of vinyl pyridine; the addition of methylene chloride resulted in a total mass concentration of vinylpyridine, iodinating agent and fluorophosphite of 24.7%.
Example 6
An ionic copolymer binder having the chemical structure:
the preparation method of the ionic copolymer binder comprises the following steps: under nitrogen atmosphere, 300g of vinylpyridine phosphate (2-vinyl-N-methylpyridine quaternary ammonium hexafluorophosphate), 300g of polyethylene glycol acrylate, 0.60g of initiator (azodiisobutyronitrile) and 5400g of solvent (N-methylpyrrolidone) are mixed in a reaction kettle, and then subjected to free radical polymerization at 70 ℃ for 7 hours, the intermediate product is precipitated into 40000g of diethyl ether, filtered, and the precipitate is dried in vacuum at 40 ℃ for 12 hours to obtain 491g of ionic copolymer binder which is named A6;
Wherein: polyethylene glycol acrylate was the same as in example 1; the ratio of the amounts of the substances of the vinylpyridine phosphate and the polyethylene glycol acrylate is 1:0.53; the mass of the initiator accounts for 0.1 percent of the sum of the mass of the vinylpyridine phosphate and the polyethylene glycol acrylate; the mass of the solvent enables the mass concentration of the vinylpyridine phosphate and the polyethylene glycol acrylate to be 10%;
the structural formula of the 2-vinyl-N-methylpyridine quaternary ammonium hexafluorophosphate is as follows:
wherein R is 1 Is methyl, R 2 Is hydrogen;
the preparation method of the 4-styryl-N-methylpyridine quaternary ammonium hexafluorophosphate comprises the following steps:
(1) 152g of 2-vinylpyridine, 221g of methyl iodide and 0.30g of benzoquinone are dissolved in 4000g of methylene dichloride, and stirred for 6 hours at 25 ℃ to carry out methylation reaction to obtain an intermediate product;
(2) Mixing the intermediate product obtained in the step (1) with 863g of ammonium hexafluorophosphate, stirring for 8 hours at 25 ℃, carrying out anion replacement reaction, and then filtering to obtain a white solid; the white solid was dried under vacuum at 60℃for 12h to give 277 g of 2-vinyl-N-methylpyridine quaternary ammonium hexafluorophosphate; wherein: the ratio of the amounts of the substances of 2-vinylpyridine, methyl iodide and ammonium hexafluorophosphate in step (1) to those in step (2) is 0.27:0.29:1; the mass of benzoquinone is 0.2% of the mass of vinyl pyridine; the addition of methylene chloride resulted in a total mass concentration of vinylpyridine, iodinating agent and fluorophosphite of 23.6%.
Comparative example 1
400g of PVDF (HSV 900) and 3600g of N-methylpyrrolidone are mixed in a reaction vessel and stirred for 12h at 25℃to give binder solution B1.
Comparative example 2
100g of sodium carboxymethylcellulose powder (Shenzhen Ke Jing, MAC500 LC), 428g of styrene-butadiene rubber emulsion (Shenzhen Ke Jing, S2919, mass fraction of polymer is 35%) and 4500g of purified water (resistivity greater than 0.1MΩ & cm) are mixed in a reaction kettle and stirred at 25 ℃ for 12 hours to obtain a binder solution B2.
Application examples 1 to 6
The ionic copolymer binders A1 to A6 prepared in examples 1 to 6 are respectively used as the ionic copolymer binders in the following preparation method step 1), and the positive electrode plates of the lithium ion batteries are prepared by sequentially C1 to C6, for example: the positive electrode sheet prepared using the ionic copolymer binder A1 of example 1 was C1, and so on;
the preparation method of the positive plate of the lithium ion battery comprises the following steps:
1) 10g of an ionic copolymer binder was dissolved in 90g of N-methylpyrrolidone to give a binder solution having a viscosity of 11 Pa.s;
2) Ball milling 80g of lithium iron phosphate and 10g of superconducting carbon black for 2 hours at 1008rpm to obtain mixed powder; wherein the mass ratio of the positive electrode active material to the conductive agent to the ionic copolymer binder is 80:10:10;
3) Ball milling the binder solution obtained in the step 1) and the mixed powder obtained in the step 2) for 4 hours at 1008rpm, adding 100g of N-methyl pyrrolidone, and continuing ball milling for 4 hours to obtain anode slurry;
4) Coating the positive electrode slurry obtained in the step 3) on aluminum foil by a knife coater, firstly drying at 60 ℃ and normal pressure for 12 hours, then drying at 80 ℃ in vacuum for 12 hours, rolling and cutting to obtain the positive electrode plate of the lithium ion battery.
Application examples 7 to 12
The ionic copolymer binders A1 to A6 prepared in examples 1 to 6 are respectively used as the ionic copolymer binder in the step 1), and the negative electrode plate of the lithium ion battery is prepared by sequentially C7 to C12, such as: the negative electrode sheet prepared using the ionic copolymer binder A1 of example 1 was C7, and so on;
the preparation method of the lithium ion battery negative electrode plate comprises the following steps:
1) 10g of an ionic copolymer binder was dissolved in 90g of N-methylpyrrolidone to give a binder solution having a viscosity of 11 Pa.s;
2) Ball milling 80g of artificial graphite and 10g of superconducting carbon black for 2 hours at 1008rpm to obtain mixed powder; wherein the mass ratio of the anode active material to the conductive agent to the ionic copolymer binder is 80:10:10;
3) Ball milling the binder solution obtained in the step 1) and the mixed powder obtained in the step 2) for 4 hours at 1008rpm, adding 100g of N-methylpyrrolidone, and continuing ball milling for 4 hours to obtain negative electrode slurry;
4) And (3) coating the negative electrode slurry obtained in the step (3) on a copper foil by using a knife coater, firstly drying at 60 ℃ and normal pressure for 12 hours, then drying at 80 ℃ in vacuum for 12 hours, rolling and cutting to obtain the negative electrode plate of the lithium ion battery.
Comparative application example 1
The preparation method of the positive plate of the lithium ion battery comprises the following steps:
1) The binder B1 prepared in comparative example 1 was used as a binder solution;
2) Ball milling 80g of lithium iron phosphate and 10g of superconducting carbon black for 2 hours at 1008rpm to obtain mixed powder;
3) Ball milling the binder solution obtained in the step 1) and the mixed powder obtained in the step 2) for 4 hours at 1008rpm, adding 100g of N-methyl pyrrolidone, and continuing ball milling for 4 hours to obtain anode slurry;
4) Coating the positive electrode slurry obtained in the step 3) on aluminum foil by a knife coater, firstly drying at 60 ℃ and normal pressure for 12 hours, then drying at 80 ℃ in vacuum for 12 hours, rolling and cutting to obtain the positive electrode plate of the lithium ion battery, wherein the number is C13.
Comparative application example 2
The preparation method of the lithium ion battery negative electrode plate comprises the following steps:
1) The binder B2 prepared in comparative example 2 was used as a binder solution;
2) Ball milling 80g artificial graphite and 10g superconducting carbon black for 2 hours at 1008rpm to obtain mixed powder;
3) Ball milling the binder solution obtained in the step 1) and the mixed powder obtained in the step 2) for 4 hours at 1008rpm, adding 100g of N-methylpyrrolidone, and continuing ball milling for 4 hours to obtain negative electrode slurry;
4) Coating the negative electrode slurry obtained in the step 3) on a copper foil by using a knife coater, firstly drying at 60 ℃ and normal pressure for 12 hours, then drying at 80 ℃ in vacuum for 12 hours, rolling and cutting to obtain the negative electrode plate of the lithium ion battery, wherein the number is C14.
Test example 1
Viscosity average molecular weight M of the Ionic copolymer binders prepared in examples 1 to 6 η Measured according to the GB/T10247-2008 test method; the thermal decomposition temperature of the ionic copolymer binder was determined by thermogravimetric analysis (German relaxation resistance, TG 209) and was increased from 25℃to 600℃at a rate of 10℃for a min under nitrogen atmosphere -1 The specific results are shown in Table 1:
TABLE 1 Performance index of ionic copolymer binders
| Adhesive agent | Solid content (%) | Viscosity average molecular weight M η (Da) | Thermal decomposition temperature (. Degree. C.) |
| A1 | 10 | 1.66×10 5 | 321 |
| A2 | 10 | 1.66×10 5 | 334 |
| A3 | 10 | 1.51×10 5 | 336 |
| A4 | 10 | 1.47×10 5 | 327 |
| A5 | 10 | 1.67×10 5 | 319 |
| A6 | 10 | 1.67×10 5 | 325 |
As can be seen from Table 1, the molecular weight of the ionic copolymer binder was 1.4X10 5 ～1.7×10 5 In Da, far below the commercial PVDF molecular weights, for example PVDF HSV900 (molecular weight 6.0X10) 5 Da), it is expected that under equivalent conditions, slurries prepared with the ionic copolymer binders of the present invention have lower viscosities and are easier to coat; the thermal decomposition of the ionic copolymer binder is higher than that of PVDF (316 ℃), so that the ionic copolymer binder has good heat resistanceAnd the performance meets the requirement of the battery running at high temperature.
Test example 2
The surface density of the active substances of the positive pole pieces C1 to C6 and C13 of the lithium ion battery is calculated as the mass of lithium iron phosphate in unit area; the peel strength between the dried slurry coating on the surface of the current collector in the pole piece and the current collector is measured according to the GB/T2791-1995 test method; the areal density and peel strength are shown in table 2.
The battery was assembled using C1 to C6 and C13, and the assembling method was as follows:
lithium hexafluorophosphate commercial electrolyte is used as electrolyte, the concentration is 1mol/L, the molar ratio of ethylene carbonate, dimethyl carbonate and diethyl carbonate is 1:1:1, a polypropylene microporous membrane (Celgard 2325) is used as a diaphragm, and lithium metal is used as a counter electrode to assemble the lithium ion battery; wherein, C1-C6 and C13 are respectively the positive electrode of the battery, and lithium metal is the negative electrode of the battery.
The specific capacity of the battery refers to the initial discharge specific capacity and 500-cycle discharge specific capacity of the assembled lithium iron phosphate/metal lithium battery under the current density of 1C, the battery cycle tester (Wuhan blue electricity, CT 3002A) of the tester is 2.5-4.2V in terms of voltage, the testing temperature is 25 ℃, the multiplying power is 1C, and the standard specific capacity of an active substance is 170mAh/g. The results of testing the surface density, peel strength, initial specific discharge capacity of the battery, specific discharge capacity at 500 th turn, and retention (ratio of specific discharge capacity to initial specific discharge capacity) of the obtained lithium iron phosphate sheet are shown in table 2.
TABLE 2 Performance index of lithium iron phosphate/lithium Metal batteries
As can be seen from Table 2, under the condition of similar surface density of the lithium iron phosphate, the lithium iron phosphate pole pieces C1-C6 prepared by using the ionic copolymer binder have higher peel strength. Compared with the lithium iron phosphate/metal lithium battery assembled by the pole piece C13 using the PVDF binder, the lithium iron phosphate/metal lithium battery assembled by the lithium iron phosphate pole pieces C1-C6 prepared by using the ionic copolymer binder has higher initial discharge specific capacity and higher discharge specific capacity and capacity retention rate after 500 cycles at the current density of 1C.
Wherein C3 is the positive electrode of the battery, and the long-cycle charge and discharge performance test of the battery assembled by the lithium metal as the negative electrode of the battery under the multiplying power conditions of 25 ℃ and cutoff voltage of 2.5-4.2V and 1C is shown in figure 1; the charge and discharge curves at 25℃with cut-off voltages of 2.5-4.2V and magnifications of 0.5C, 1C, 2C and 3C are shown in FIG. 2. As can be seen from fig. 1, in a long cycle with a current density of 1C, the battery has a high specific discharge capacity and coulombic efficiency, and the capacity retention at 500 th turn is also high. As can be seen from fig. 2, at each current density, a higher specific discharge capacity can be exhibited. Even at high current densities of 3C, the desired specific capacity is still exhibited. When the current density returns again to 0.5C, the specific capacity also smoothly returns to the value just started.
Test example 3
The mass of the artificial graphite on the unit area of the surface density of the active substances of the negative electrode pieces C7-C12 and C14 of the lithium ion battery is calculated; the peel strength between the dried slurry coating on the current collector surface in the pole piece and the current collector was determined according to the GB/T2791-1995 test method. The areal density and peel strength are shown in Table 3.
The battery was assembled using C7 to C12 and C14, and the method of assembly was as follows:
lithium hexafluorophosphate commercial electrolyte is used as electrolyte, the concentration is 1mol/L, the molar ratio of ethylene carbonate, dimethyl carbonate and diethyl carbonate is 1:1:1, a polypropylene microporous membrane (Celgard 2325) is used as a diaphragm, and lithium metal is used as a counter electrode to assemble the lithium ion battery. Wherein the artificial graphite pole piece is a battery anode, and the lithium metal is a battery cathode.
The specific capacity of the battery refers to the initial discharge specific capacity and 500-cycle discharge specific capacity of the assembled artificial graphite/metal lithium battery under the current density of 1C, the battery cycle tester (Wuhan blue electricity, CT 3002A) of the testing instrument is 0.005-1.5V in voltage, the testing temperature is 25 ℃, the multiplying power is 1C, and the standard specific capacity of the active substance is 374mAh/g. The results of testing the surface density, peel strength, initial specific discharge capacity of the battery, specific discharge capacity at 500 th turn and retention (ratio of specific discharge capacity to specific initial discharge capacity) of the resulting artificial graphite sheet are shown in table 3.
TABLE 3 Performance index of artificial graphite/metallic lithium batteries
As can be seen from Table 3, the peel strength of the artificial graphite pole pieces C7-C12 prepared with the ionic copolymer binder of the present invention was higher than that of the artificial graphite pole piece C14 prepared with the CMC/SBR binder at similar areal densities. Compared with the artificial graphite/metal lithium battery assembled by the pole piece C14 using the CMC/SBR binder, the artificial graphite/metal lithium battery assembled by the artificial graphite pole pieces C7-C12 prepared by using the ionic copolymer binder has similar initial discharge specific capacity, and after 500 circles of circulation under the current density of 1C, the artificial graphite pole piece prepared by using the ionic copolymer binder has higher or similar discharge specific capacity and capacity retention rate, so that the long-circulation performance is better.
Test example 4
The prepared C3 or C13 is taken as a lithium iron phosphate positive electrode plate, the C8 or C14 is taken as an artificial graphite negative electrode plate, and the assembled lithium iron phosphate/artificial graphite battery comprises the following steps:
lithium hexafluorophosphate commercial electrolyte is used as electrolyte, the concentration is 1mol/L, the molar ratio of ethylene carbonate, dimethyl carbonate and diethyl carbonate is 1:1:1, and a polypropylene microporous membrane (Celgard 2325) is used as a diaphragm to obtain lithium iron phosphate/artificial graphite batteries which are respectively named as D1-D4.
The assembled lithium iron phosphate 1-4/artificial graphite battery is subjected to battery cycle test in a battery cycle tester (Wuhan blue electricity, CT 3002A), wherein the cut-off voltage is 2.5-4.2V, the test temperature is 25 ℃, the multiplying power is 1C, and the standard specific capacity of an active substance is 170mAh/g. The results of the test to obtain the initial specific capacity of the battery cycle, the specific capacity of the 1000 th turn discharge and the capacity retention (the ratio of the specific capacity of discharge to the specific capacity of initial discharge) are shown in table 4.
TABLE 4 Performance index of lithium iron phosphate/artificial graphite batteries
The full cell performance results in table 4 further show that the full cell assembled with the lithium iron phosphate positive electrode sheet C3 and the artificial graphite negative electrode sheet C8 prepared by using the ionic copolymer binder of the present invention, and the full cell assembled with the artificial graphite negative electrode sheet C14 prepared by SBR/CMC binder and the lithium iron phosphate positive electrode sheet C13 prepared by PVDF binder, respectively, has higher or similar discharge specific capacity and long cycle capacity retention rate of the cell after 1000 cycles at a current density of 1C, and in particular, D1 full cell performance is optimal, compared with the full cell assembled with the lithium iron phosphate positive electrode sheet C13 prepared by PVDF binder and the artificial graphite negative electrode sheet C14 prepared by SBR/CMC binder.
As can be seen from the results of the above examples, when the ionic copolymer binder provided by the present invention is used for preparing a positive electrode sheet of a lithium ion battery and a negative electrode sheet of a lithium ion battery, the ionic copolymer binder provided by the present invention has excellent adhesion with an active material, because the ionic copolymer binder provided by the present invention is a copolymer of vinylpyridine phosphate containing hexafluorophosphate ion groups and polyethylene glycol acrylate, the coulomb force between hexafluorophosphate in the ionic copolymer binder and the positive electrode or negative electrode active material can enhance the adhesion between materials; polyethylene glycol acrylic ester can improve the flexibility of the adhesive on one hand, soften the pole piece, and improve the ion transmission performance of an interface on the other hand, so that the lithium ion battery assembled by using the adhesive has higher specific capacity, capacity retention rate and cycle stability.
The foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention.
Claims (10)
1. An ionic copolymer binder characterized by having a chemical structure as shown in formula I:
In the formula I, R 1 Is alkyl, R 2 Is hydrogen, alkyl or aralkyl, R 3 Is hydrogen or alkyl, n=4 to 40, m=50 to 900, q=0 to 1200.
2. The method of preparing the ionic copolymer binder of claim 1, comprising: mixing vinylpyridine phosphate, polyethylene glycol acrylic ester, an initiator and a solvent in inert atmosphere, and then carrying out free radical polymerization reaction to obtain an ionic copolymer binder;
the vinyl pyridine phosphate has a chemical structure shown in a formula II, and the polyethylene glycol acrylate has a chemical structure shown in a formula III:
in the formula II, R 1 Is alkyl, R 2 Is hydrogen, alkyl or aralkyl;
in the formula III, R 3 Is hydrogen or alkyl, and n is 4-40.
3. The preparation method according to claim 2, characterized in that the preparation method of the vinylpyridine phosphate comprises the following steps:
(1) Mixing vinyl pyridine, an iodizing agent, a polymerization inhibitor and a solvent for methylation reaction to obtain an intermediate product;
(2) And (3) mixing the intermediate product obtained in the step (1) with fluorophosphite to carry out negative ion replacement reaction to obtain the vinylpyridine phosphate.
4. The process according to claim 3, wherein the ratio of the amounts of the vinyl pyridine, the iodinating agent and the fluorophosphite salt in the step (1) is (0.1 to 0.3): 0.2 to 0.4): 1.
5. The method according to claim 3, wherein the temperature of the methylation reaction in the step (1) and the temperature of the anion exchange reaction in the step (2) are independently 10 to 45 ℃; the time of methylation reaction and the time of anion exchange reaction are independently 1-12 h.
6. The preparation method according to claim 2, wherein the ratio of the amounts of the substances of the vinylpyridine phosphate and the polyethylene glycol acrylate is 1 (0.3 to 1.1).
7. The method according to claim 2, wherein the temperature of the radical polymerization is 45 to 80 ℃ and the time of the radical polymerization is 6 to 24 hours.
8. The use of the ionic copolymer binder of claim 1 or the ionic copolymer binder prepared by the preparation method of any one of claims 2 to 7 in electrode plates of lithium ion batteries.
9. The use according to claim 8, wherein the preparation method of the electrode sheet of the lithium ion battery comprises the following steps:
1) Dissolving an ionic copolymer binder in an organic solvent to obtain a binder solution;
2) Mixing an active substance and a conductive agent to obtain mixed powder;
3) Mixing the binder solution obtained in the step 1), the mixed powder obtained in the step 2) and an organic solvent to obtain electrode slurry;
4) Coating the electrode slurry obtained in the step 3) on a current collector to obtain a positive plate of the lithium ion battery;
the step 1) and the step 2) are not in sequence.
10. The use according to claim 8 or 9, wherein the lithium ion battery electrode sheet is a positive electrode sheet or a negative electrode sheet.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311421707.5A CN117219775B (en) | 2023-10-31 | 2023-10-31 | Ionic copolymer binder and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311421707.5A CN117219775B (en) | 2023-10-31 | 2023-10-31 | Ionic copolymer binder and preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN117219775A true CN117219775A (en) | 2023-12-12 |
| CN117219775B CN117219775B (en) | 2024-08-20 |
Family
ID=89039174
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311421707.5A Active CN117219775B (en) | 2023-10-31 | 2023-10-31 | Ionic copolymer binder and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117219775B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118240508A (en) * | 2024-03-22 | 2024-06-25 | 南开大学 | Ionic polymer binder and preparation method and application thereof |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5017646A (en) * | 1986-01-08 | 1991-05-21 | Hisaichi Muramoto | Aqueous vinyl resin emulsion |
| US6770397B1 (en) * | 1999-07-15 | 2004-08-03 | Zeon Corporation | Binder composition for lithium ion secondary battery electrodes and use thereof |
| CN103537321A (en) * | 2013-10-17 | 2014-01-29 | 南开大学 | Polymer-supported ionic liquid and preparation method thereof as well as application of polymer-supported ionic liquid in catalytic esterification |
| WO2016114241A1 (en) * | 2015-01-16 | 2016-07-21 | 日東電工株式会社 | Double-sided pressure-sensitive adhesive sheet |
| WO2019004431A1 (en) * | 2017-06-29 | 2019-01-03 | 株式会社Adeka | Adhesive composition |
| CN110137569A (en) * | 2019-05-21 | 2019-08-16 | 南开大学 | A kind of preparation method and application of sodium base PEG/PMA composite polymer electrolyte |
| CN110699020A (en) * | 2019-11-20 | 2020-01-17 | 湖南大学 | Polyion liquid adhesive and preparation method thereof |
| CN111600033A (en) * | 2020-05-28 | 2020-08-28 | 珠海冠宇电池股份有限公司 | Negative electrode binder and application thereof |
| CN111635478A (en) * | 2020-06-10 | 2020-09-08 | 珠海冠宇电池股份有限公司 | Low-impedance binder and preparation method and application thereof |
| CN115528245A (en) * | 2021-06-24 | 2022-12-27 | 深圳市比亚迪锂电池有限公司 | Conductive binder, preparation method thereof, silicon negative electrode, lithium battery and vehicle |
| CN116875234A (en) * | 2023-07-25 | 2023-10-13 | 阿梓萨科技(深圳)有限公司 | Preparation method of cathode binder of cathode and anode polymer composite battery |
-
2023
- 2023-10-31 CN CN202311421707.5A patent/CN117219775B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5017646A (en) * | 1986-01-08 | 1991-05-21 | Hisaichi Muramoto | Aqueous vinyl resin emulsion |
| US6770397B1 (en) * | 1999-07-15 | 2004-08-03 | Zeon Corporation | Binder composition for lithium ion secondary battery electrodes and use thereof |
| CN103537321A (en) * | 2013-10-17 | 2014-01-29 | 南开大学 | Polymer-supported ionic liquid and preparation method thereof as well as application of polymer-supported ionic liquid in catalytic esterification |
| WO2016114241A1 (en) * | 2015-01-16 | 2016-07-21 | 日東電工株式会社 | Double-sided pressure-sensitive adhesive sheet |
| WO2019004431A1 (en) * | 2017-06-29 | 2019-01-03 | 株式会社Adeka | Adhesive composition |
| CN110137569A (en) * | 2019-05-21 | 2019-08-16 | 南开大学 | A kind of preparation method and application of sodium base PEG/PMA composite polymer electrolyte |
| CN110699020A (en) * | 2019-11-20 | 2020-01-17 | 湖南大学 | Polyion liquid adhesive and preparation method thereof |
| CN111600033A (en) * | 2020-05-28 | 2020-08-28 | 珠海冠宇电池股份有限公司 | Negative electrode binder and application thereof |
| CN111635478A (en) * | 2020-06-10 | 2020-09-08 | 珠海冠宇电池股份有限公司 | Low-impedance binder and preparation method and application thereof |
| CN115528245A (en) * | 2021-06-24 | 2022-12-27 | 深圳市比亚迪锂电池有限公司 | Conductive binder, preparation method thereof, silicon negative electrode, lithium battery and vehicle |
| CN116875234A (en) * | 2023-07-25 | 2023-10-13 | 阿梓萨科技(深圳)有限公司 | Preparation method of cathode binder of cathode and anode polymer composite battery |
Non-Patent Citations (6)
| Title |
|---|
| AKIMICHI OHTSUKI，ET AL.: "Photocontrolled Organocatalyzed Living Radical Polymerization Feasible over a Wide Range of Wavelengths", 《J. AM. CHEM. SOC.》, vol. 137, no. 16, 16 April 2015 (2015-04-16), pages 5610 * |
| BING YUAN，ET AL.: "Self-assembly synthesis of solid polymer electrolyte with carbonate terminated poly(ethylene glycol) matrix and its application for solid state lithium battery", 《JOURNAL OF ENERGY CHEMISTRY》, vol. 38, 10 January 2019 (2019-01-10), pages 55 - 59, XP085728781, DOI: 10.1016/j.jechem.2019.01.004 * |
| BINMIN WANG，ET AL.: "Multifunctional Underwater Adhesive Film Enabled by a Single-Component Poly(ionic liquid)", 《ACS NANO》, vol. 17, no. 6, 16 March 2023 (2023-03-16), pages 5871 * |
| WEN JING YANG，EA TL.: "Two-stage thiol-based click reactions for the preparation and adhesion of hydrogels", 《POLYMER CHEMISTRY》, vol. 11, no. 17, 6 April 2020 (2020-04-06), pages 2986 - 2994 * |
| 吕娟，等: "带有可调通道的嵌段共聚物胶束对药物的控制释放", 高等学校化学学报, no. 05, 10 May 2007 (2007-05-10), pages 982 - 986 * |
| 杨木泉，等: "Au/聚4-乙烯基吡啶-b-聚乙二醇嵌段聚合物刷的合成及其pH响应行为", 《应用化学》, vol. 36, no. 4, 10 April 2019 (2019-04-10), pages 431 - 439 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118240508A (en) * | 2024-03-22 | 2024-06-25 | 南开大学 | Ionic polymer binder and preparation method and application thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN117219775B (en) | 2024-08-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1629556B1 (en) | Composite binder for an electrode with dispersants chemically bound | |
| KR100800969B1 (en) | Electrode Material Containing Polyvinyl Alcohol as Binder and Rechargeable Lithium Battery Comprising the Same | |
| CN111635478B (en) | Low-impedance binder and preparation method and application thereof | |
| JPH1167213A (en) | Composition for battery electrode and battery electrode | |
| CN117219775B (en) | Ionic copolymer binder and preparation method and application thereof | |
| JP6922888B2 (en) | Binder composition for non-aqueous secondary battery electrodes, conductive material paste composition for non-aqueous secondary battery electrodes, slurry composition for non-aqueous secondary battery electrodes, non-aqueous secondary battery electrodes and non-aqueous secondary batteries | |
| CN113571692B (en) | High-safety conductive material modified high-nickel positive electrode material and preparation method thereof | |
| US20200067076A1 (en) | Materials for lithium-ion electrochemical cells and methods of making and using same | |
| CN106711460B (en) | Electrode slurry composition and application thereof in preparing electrode and lithium ion battery | |
| CN111801822A (en) | Binder composition for nonaqueous secondary battery electrode, conductive material paste composition for nonaqueous secondary battery electrode, slurry composition for nonaqueous secondary battery electrode, electrode for nonaqueous secondary battery, and nonaqueous secondary battery | |
| EP3734727A1 (en) | Binder composition for secondary battery electrode, and electrode mixture | |
| CN112786889A (en) | Binder, negative electrode slurry, negative electrode and lithium ion battery | |
| CN112072091A (en) | Negative electrode, method for producing same, and lithium ion battery using same | |
| CN117089017A (en) | Non-fluorine binder for positive electrode of lithium ion battery, positive electrode using same and battery | |
| CN114316119B (en) | Binder and battery comprising same | |
| EP3771004A1 (en) | Binder composition for nonaqueous secondary battery electrode, conductive material paste composition for nonaqueous secondary battery electrode, slurry composition for nonaqueous secondary battery electrode, nonaqueous secondary battery electrode, and nonaqueous secondary battery | |
| CN116247207A (en) | Cross-linked adhesive for all-solid-state battery and preparation method thereof | |
| CN117487483B (en) | Ionic polymer binder and preparation method and application thereof | |
| US11978906B2 (en) | Binder for secondary battery | |
| CN112072110B (en) | Negative electrode, method for producing same, and lithium ion battery using same | |
| CN117363275B (en) | High-pressure-resistant copolymer binder, preparation method thereof and lithium ion battery | |
| KR20230061345A (en) | Binder composition for electrochemical device, conductive material dispersion for electrochemical device, slurry for electrochemical device electrode, electrode for electrochemical device and electrochemical device | |
| CN113346086A (en) | Binder, preparation method and application thereof, negative plate and lithium ion battery | |
| CN113675461A (en) | Flexible organic-inorganic hybrid solid electrolyte, preparation method thereof and battery | |
| CN117363276B (en) | Water-based polymer binder, preparation method thereof and application thereof in positive and negative plates of lithium ion battery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |